In vitro biotransformation of OA-group and PTX-group toxins in visceral and non-visceral tissues of Mytilus chilensis and Ameghinomya antiqua

ABSTRACT

Lipophilic marine toxins (LMTs) are made up of multiple groups of toxic analogues, which are characterised by different levels of cellular and toxic action. The most prevalent groups in the southern Pacific zone are: a) okadaic acid group (OA-group) which consists of okadaic acid (OA) and dinophysistoxin-1 (DTX-1); and, b) pectenotoxin-2 (PTX2) group which consists of pectenotoxin-2 (PTX-2). The main objective of our study was to examine in vitro biotransformation of OA-group and PTX-group in the tissues of two endemic species of bivalves from southern Chile; blue mussels (Mytilus chilensis) and clams (Ameghinomya antiqua). The biotransformation processes of both groups were only detected in the digestive glands of both species using LC-MS/MS. The most frequently detected analogues were acyl derivatives (≈2.0 ± 0.1 μg ml⁻¹) for OA-group and PTX-2SA (≈1.4 ± 0.1 μg ml⁻¹) for PTX-group, with a higher percentage of biotransformation for OA-group (p < .001). In addition, simultaneous incubations of the different analogues (OA/PTX-2; DTX-1/PTX-2 and OA/DTX-1/PTX-2) did not show any interaction between the biotransformation processes. These results show that the toxicological variability of endemic species leads to biotransformation of the profile of toxins, so that these new analogues may affect people’s health.

KEYWORDS:

• Okadaic acid-group
• acyl derivatives
• pectenotoxin-group
• pectenotoxin-2sa
• transformation
• Mytilus chilensis
• Ameghinomya antiqua

Acknowledgments

This study was performed with funds from Fondo Nacional de Ciencia y Tecnología (“Chilean National Science and Technology Fund”) (FONDECYT) Number 1160168 (granted to C. García). The authors thank the Secretaría Regional Ministerial de Salud de la Región de Aysén (“Aysén Regional Health Ministry”) and Capitanía de Puerto de Puerto Aguirre, Armada de Chile (“Port Authority of Puerto Aguirre, Chilean Navy”).

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

This work was supported by the Fondo Nacional de Desarrollo Científico y Tecnológico [1160168].